1. FIELD OF THE INVENTION
This invention relates to improvements in subsurface pumps and more particularly to a traveling valve assembly providing a positive shut off and seal for preventing fluid loss and controlling gas or air pressure which might otherwise damage the pumping system.
2. BRIEF DESCRIPTION OF THE PRIOR ART
In producing oil wells it is common practice to provide a pump at the bottom of the well bore or at least down the well in the producing formation. The pump is normally actuated by reciprocation of the pump plunger by sucker rods which extend through the well bore from a reciprocating device at the surface of the ground and into connection with the pump. The reciprocating device at the surface is usually a horsehead type pump and alternately raises and lowers the string of sucker rods in the well bore.
It is frequently necessary during the pumping operation to pull the pipe or casing from the well to repair or replace the parts of the pump which is very costly and time consuming. Failure of the pump and resulting fluid loss may be caused by wear, sand packing in the ports and moving parts, and excessive gas pressures. Pump systems are known in the prior art. There are several patents which illustrate various pump assemblies.
MaGee, U.S. Pat. No. 1,698,163 discloses a valve cage for use in the working barrels of oil wells. The device is interposed in the pump rod of the well normally preventing the downward flow of fluid therein while the pump rod is being operated, but which may be opened to prevent the return of the oil in the upper portion of the casing whenever it is desired to withdraw the pump rod or casing.
Vickers, U.S. Pat. No. 2,669,939 discloses a deep well pump comprising a lower standing valve, an outlet valve, and a relief valve which cooperate to provide a straight unobstructed course for the upward flow of the liquid being pumped. The pump may be pulled from the well without pulling the well tubing.
Stevenson, U.S. Pat. No. 2,787,964 discloses a sectional liner pump comprising a seating shoe, a stationary barrel, and an outer shell. The lower end of the shell carries a standing valve. A rod guide is fixed to the top of the seating body and a the lower end of a reciprocating rod string is fixed to a plunger which carries a traveling valve.
Wells, U.S. Pat. No. 3,212,444 discloses a pump adapted to pump liquid from multiple zones. The pump comprises an upper and lower pump barrel. A standing valve controls flow through the lower barrel and a second standing valve controls flow through the upper barrel. Reciprocating upper and lower plunger disposed in the barrels are connected by a connecting rod having a main passageway. A lower traveling valve controls the flow through the main passageway.
Tolbert, U.S. Pat. No. 3,592,567 discloses a subsurface pump wherein a passageway is provided for directing a lubricant into the annulus between the working barrel and the pump plunger for facilitating the reciprocation of the plunger. The pump comprises a lower traveling valve and an upper back pressure valve.
Other patents of interest are; Le Bus, U.S. Pat. No. 1,694,329 disclosing a rotary pump, Fisher, U.S. Pat. No. 2,815,925 disclosing valves for controlling fluids in well bores, and Redpath, U.S. Pat. No. 2,572,388 disclosing a safety joint for well swabs.
The prior art in general, and none of these patents in particular, disclose a traveling valve assembly for use in subsurface gravity type pumping systems having the advantages of the present invention. The prior art does not suggest a traveling valve assembly which is responsive to reciprocating motion to manipulate a rotary valve member relative to a valve seat between open and closed positions, and to fluid pressure to manipulate a ball member and a slidable seal member relative to seat members between open and closed positions.